1. Field of the Invention
This invention relates to a female terminal which is connected to an end of a wire harness, used in an automobile or the like, and is fitted into a connector housing (hereinafter referred to merely as "housing"), and more particularly to a female terminal which is easily insertable into a terminal receiving chamber in the housing.
2. Related Art
Usually, a connection terminal is inserted into a housing and retained in a terminal receiving chamber in the housing, and then this terminal is fitted to a mating connection terminal to make an electrical connection therebetween. Therefore, the connection terminal, when fitted to the mating connection terminal, needs to be retained by a suitable retaining means so that it will not be easily moved in the terminal receiving chamber.
Generally, an elastic retaining lance of the cantilever type having one free end is formed on at least one inner surface of the terminal receiving chamber, and this free end of the retaining lance retainingly engages a predetermined portion of the connection terminal to fix the connection terminal within the terminal receiving chamber.
The process of insertion of a conventional female terminal into a housing will now be described with reference to FIGS. 6 to 8. As shown in FIG. 6, the female terminal 20 has an electrical contact portion 20b of a cross-sectionally square, tubular configuration at its front portion, and a wire connection portion 20a at its rear portion.
For mounting the female terminal 20 in the housing 11, the female terminal 20 is first inserted into a terminal receiving chamber 14 in the housing 11 from the rear end (right end in the drawings) of this housing.
As shown in FIG. 7, a retaining hole 22 of a rectangular shape is formed through one side wall (retaining wall) 20c of the electrical contact portion 20b of a cross-sectionally square, tubular shape, and is disposed centrally of the width of the side wall 20c.
A resilient contact plate 28 for securing an electrical contact between the female terminal and a male terminal (not shown) is provided within the electrical contact portion 20b. This resilient contact plate 28 is mounted on the female terminal 20 in the process of producing this terminal. A continuous plate constituting the resilient contact plate 28 is inserted into the cross-sectionally square, tubular portion by the use of a mounting tool, and then is cut at that portion thereof which defines one end of the resulting contact plate 28, and then this contact plate is secured to the tubular portion. Therefore, a notch 24 of a rectangular shape, serving as a tool insertion hole for passing the mounting tool therethrough is formed in a front end of the retaining wall 20c.
The conventional female terminal 20 of the above construction, when inserted into the housing 11, advances in the terminal receiving chamber in a direction of arrow Z as shown in FIG. 8, so that front edges 23a and 23a of the opposite side portions of the front end of the female terminal spaced from each other by the notch 24 are brought into contact with a slanting surface 12a formed on an elastic retaining lance 12 provided on the housing 11.
In this condition, when the female terminal 20 is further advanced in the direction of arrow Z, the front edges 23a and 23a on the female terminal 20 urge the elastic retaining lance 12 to elastically deform upwardly. As a result, the front end of the female terminal 20 passes the slanting surface 12a of the retaining lance 12 to further advance in the direction of arrow Z.
Thus, the female terminal 20 further advances, with the retaining wall 20c held in sliding contact with the slanting surface 12a of the elastically-deformed retaining lance 12, and reaches a predetermined position whereupon the front end of the retaining lance 12 becomes fitted in the retaining hole 22. At this time, the retaining lance 12 is restored from the elastically-deformed condition to its original condition.
As a result, a step portion at the front end of the retaining lance 12 is engaged with the edge of the retaining hole 22, thereby retaining the female terminal 20 in the housing 11.
However, when the above conventional female terminal 20 is inserted into the housing 11, the front end of the female terminal is sometimes caught by the elastic retaining lance 12, and hence is not smoothly inserted into the predetermined position. If the female terminal is forcibly inserted, the retaining lance 12 may be damaged, or may be plastically deformed in an unrestorable manner, so that the retaining lance may lose the function of retaining the connection terminal.
More specifically, the two sharp edges 23a at the front end of the female terminal 20, contacting with the slanting surface 12a of the retaining lance 12 during the insertion, may damage this slanting surface 12a, which results in a possibility that the female terminal 20 can not be retained properly.